Control button



FIG. 1 is a top perspective view of a control button showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a top plan view of the control button with an exemplary data processing system on which the control button may be installed; and,

FIG. 4 is a top perspective view of the control button with the exemplary data processing system on which the control button may be installed.

The phantom lines showing the outline of the data processing system are for illustration purposes only and form no part of the claimed invention. 

The ornamental design for a control button, as shown and described. 